2017: Initial Prospects for Yukon Chinook Salmon Timing
Lower Yukon River (ADFG Area Y-1), May 11, 2017
The final timing forecast for Yukon River Chinook Salmon will be issued during the first week of June
This is an alert to the possibility of an early Chinook run on the Yukon delta for harvesters, managers
and the public. Under the earliest possible scenario the numbers of Chinook entering the lower river
would start building the last week of the month (May) with the first significant jump, or pulse, in
abundance expected around the end of the first week in June. April mean air temperature is the early
warning signal among the climate indicators in the timing models and analysis, providing a qualitative
first look at Chinook run timing for the Yukon delta area. The analysis of 56 past years of chinook catches
and environmental conditions teaches us to be alert for the possibility of early runs following warmer
than average Aprils. The early run flag was set when Nome experienced its second very warm April in a
row, with a mean air
temperature of 31.7F (-0.7C),
which is a substantial 12.4F
warmer than the long-term
average. Last year’s April mean
air temperature in Nome
finished above the freezing
mark (34.4F) for only the second
time since monthly records
began in 1907. Even so, a warm
April is no guarantee of an early
run. Some late runs have been
preceded by warm Aprils, which
is why the more precise
numerical timing forecast is
made later in the year when better information on sea ice and temperatures become available, enabling
forecasts of daily percentages of the run during June and early July. As the new information becomes
available at the end of May, a numerical timing forecast of percentage points of the run by date will be
displayed on the project web site along with temperatures and sea ice concentrations.
Credits
Prepared by Phil Mundy [email protected]. Statistical analysis by Bryce Mecum
[email protected]. Data management and web page support by Will Koeppen
[email protected]. Web support also provided by Holly Kent [email protected]. Yukon Chinook inseason salmon data and management agency coordination by Holly Carroll [email protected].
Financial and material supports were provided by the Alaska Ocean Observing System, NOAA National
Marine Fisheries Service and the Alaska Department of Fish and Game.
Initial Prospects for 2017 Timing of Yukon River Chinook May 8, 2017, Page 1 of 1